The present invention relates to keyboard supports to be attached to work surfaces and in particular relates to an height adjustable keyboard support arrangement.
There are many examples of adjustable keyboard support arrangements for attachment to and adjacent one edge of a work surface. These different arrangements can be sub-divided into two design types. The first design is a monoarm arrangement which can either be fixed to the underside of the work surface or is slidably mounted beneath the work surface. The keyboard or keyboard support surface is mounted to the central arm and basically extends either side of the central arm. With this arrangement, the monoarm is positioned centrally and can include a parallel linkage arrangement or other adjustable arm mechanisms for varying the support height for the keyboard.
The second design uses two parallel arm mechanisms interconnected by a central member. These arms are widely spaced and support the keyboard support surface generally adjacent either end of thereof. An example of such a mechanism is shown in U.S. Pat. No. 5,398,622. These parallel support arm mechanisms can be slidably attached beneath a work surface or can be fixed to the work surface. The mechanism can include different types of linkages either for maintaining the angle of the keyboard support surface with changes in height or allowing some correction in the angle as the height of the keyboard support work surface is changed.
With these mechanisms, an operator can adjust the height of the keyboard and adjust the angle of the keyboard according to their own preference. It also allows different operators to adjust the keyboard support work surface according to their own preference.
Both the monoarm design and the two parallel arm arrangement restrict the clear area beneath the work surface and keyboard surface. This restricts the leg space available to the operator. Furthermore, it can be appreciated that the keyboard support work surface extends from one side of the work surface and an operator often has their legs beneath the keyboard support which can be at a relatively low position. Should the operator have to stand up quickly or should the height of the work surface change quickly, the keyboard support surface can result in undesired contact with the operator's thighs.
Both the monoarm design and the twin parallel arm mechanisms are known to have a counterbalance arrangement for safety and to ease adjustment in the height of the keyboard.